BECKHOFF DK9222-1109-0015 - Manual (Page 4)

I/O
Wireless Automation
Application Note DK9222-1109-0015
CU8890 – operating modes: client or access point
Client​drivers​are​available​for​Windows​XP,​Embedded​Standard​and​Windows​CE,​and​therefore​for​any​Beckhoff​Industrial​
and​Embedded​PC.​Due​to​the​drivers​for​Windows​XP​and​Embedded​Standard,​the​CU8890​can​also​be​operated​as​an​
access​point.​Encryption​mechanisms​are​possible​with​AES​128‑bit​up​to​WPA2.​The​module​is​Cisco‑CCX‑compatible​and​
supports​PEAP​and​LEAP.​The​data​rate​is​adjusted​dynamically​up​to​54​Mbit/s​(gross).​The​CU8890​has​a​reverse​SMA​plug​for​
connecting​the​antenna,​this​way​the​antennas​can​be​adapted​to​the​environment.
​
Laptop
USB
CU8890
USB
1
USB
2
USB
n
CU8890 CU8890 CU8890
CU8890 as access point CU8890 as client
Access point (corporate network)
Fig. 2 left – access point, right – WLAN client
2. Coexistence – simultaneous operation of radio systems
A​radio​network​is​a​jointly​used​medium;​therefore,​all​participants​must​share​the​transmission​link.​It​is​ensured​within​
the​network​that​the​available​bandwidth​is​distributed​among​the​devices.​There​are​two​possible​methods​here.​Either​one​
device​may​use​the​entire​bandwidth​for​a​certain​period​of​time​while​all​other​devices​wait.​Upon​expiry​of​this​transmission​
time,​the​communication​is​interrupted​and​it​is​then​the​next​device’s​turn.​Or​a​device​is​provided​only​with​one​small​
part​of​the​bandwidth​(a​channel),​which​it​can​use​for​data​transmission.​The​following​systems​use​the​2.4​GHz​band:​
WLAN,​IEEE​802.15.4,​Bluetooth​and​other​proprietary​technologies.​Proprietary​technologies​are​systems​made​by​various​
manufacturers​that​are​not​standardised,​e.g.​baby​phones,​radio​transmission​systems​for​video​signals​and​the​like.
New Automation Technology Beckhoff
For​application​notes​see​disclaimer​on​the​last​page